A typical inverter includes a noise filter. The noise filter reduces common mode noise and normal mode noise. Patent Document 1 discloses an inverter device that converts the output of an alternating-current (AC) power supply into direct-current (DC) power with a rectifier, converts the DC power into desired AC power with an inverter circuit, and supplies the AC power to a load. In this case, current flows between an AC neutral point of the load and an output neutral point of the rectifier. The inverter device includes means for generating a cancellation current that cancels the current with current flowing from the output AC neutral point of the AC power supply toward ground to reduce leakage current resulting from potential fluctuation at the AC neutral point of the load.